// This file is part of Eigen, a lightweight C++ template library
// for linear algebra.
//
// Copyright (C) 2006-2008 Benoit Jacob <jacob.benoit.1@gmail.com>
// Copyright (C) 2008 Gael Guennebaud <gael.guennebaud@inria.fr>
//
// This Source Code Form is subject to the terms of the Mozilla
// Public License v. 2.0. If a copy of the MPL was not distributed
// with this file, You can obtain one at http://mozilla.org/MPL/2.0/.

#ifndef EIGEN_IO_H
#define EIGEN_IO_H

namespace Eigen {

enum
{
    DontAlignCols = 1
};
enum
{
    StreamPrecision = -1,
    FullPrecision = -2
};

namespace internal {
    template <typename Derived> std::ostream& print_matrix(std::ostream& s, const Derived& _m, const IOFormat& fmt);
}

/** \class IOFormat
  * \ingroup Core_Module
  *
  * \brief Stores a set of parameters controlling the way matrices are printed
  *
  * List of available parameters:
  *  - \b precision number of digits for floating point values, or one of the special constants \c StreamPrecision and \c FullPrecision.
  *                 The default is the special value \c StreamPrecision which means to use the
  *                 stream's own precision setting, as set for instance using \c cout.precision(3). The other special value
  *                 \c FullPrecision means that the number of digits will be computed to match the full precision of each floating-point
  *                 type.
  *  - \b flags an OR-ed combination of flags, the default value is 0, the only currently available flag is \c DontAlignCols which
  *             allows to disable the alignment of columns, resulting in faster code.
  *  - \b coeffSeparator string printed between two coefficients of the same row
  *  - \b rowSeparator string printed between two rows
  *  - \b rowPrefix string printed at the beginning of each row
  *  - \b rowSuffix string printed at the end of each row
  *  - \b matPrefix string printed at the beginning of the matrix
  *  - \b matSuffix string printed at the end of the matrix
  *  - \b fill character printed to fill the empty space in aligned columns
  *
  * Example: \include IOFormat.cpp
  * Output: \verbinclude IOFormat.out
  *
  * \sa DenseBase::format(), class WithFormat
  */
struct IOFormat
{
    /** Default constructor, see class IOFormat for the meaning of the parameters */
    IOFormat(int _precision = StreamPrecision,
             int _flags = 0,
             const std::string& _coeffSeparator = " ",
             const std::string& _rowSeparator = "\n",
             const std::string& _rowPrefix = "",
             const std::string& _rowSuffix = "",
             const std::string& _matPrefix = "",
             const std::string& _matSuffix = "",
             const char _fill = ' ')
        : matPrefix(_matPrefix), matSuffix(_matSuffix), rowPrefix(_rowPrefix), rowSuffix(_rowSuffix), rowSeparator(_rowSeparator), rowSpacer(""),
          coeffSeparator(_coeffSeparator), fill(_fill), precision(_precision), flags(_flags)
    {
        // TODO check if rowPrefix, rowSuffix or rowSeparator contains a newline
        // don't add rowSpacer if columns are not to be aligned
        if ((flags & DontAlignCols))
            return;
        int i = int(matSuffix.length()) - 1;
        while (i >= 0 && matSuffix[i] != '\n')
        {
            rowSpacer += ' ';
            i--;
        }
    }
    std::string matPrefix, matSuffix;
    std::string rowPrefix, rowSuffix, rowSeparator, rowSpacer;
    std::string coeffSeparator;
    char fill;
    int precision;
    int flags;
};

/** \class WithFormat
  * \ingroup Core_Module
  *
  * \brief Pseudo expression providing matrix output with given format
  *
  * \tparam ExpressionType the type of the object on which IO stream operations are performed
  *
  * This class represents an expression with stream operators controlled by a given IOFormat.
  * It is the return type of DenseBase::format()
  * and most of the time this is the only way it is used.
  *
  * See class IOFormat for some examples.
  *
  * \sa DenseBase::format(), class IOFormat
  */
template <typename ExpressionType> class WithFormat
{
public:
    WithFormat(const ExpressionType& matrix, const IOFormat& format) : m_matrix(matrix), m_format(format) {}

    friend std::ostream& operator<<(std::ostream& s, const WithFormat& wf) { return internal::print_matrix(s, wf.m_matrix.eval(), wf.m_format); }

protected:
    typename ExpressionType::Nested m_matrix;
    IOFormat m_format;
};

namespace internal {

    // NOTE: This helper is kept for backward compatibility with previous code specializing
    //       this internal::significant_decimals_impl structure. In the future we should directly
    //       call digits10() which has been introduced in July 2016 in 3.3.
    template <typename Scalar> struct significant_decimals_impl
    {
        static inline int run() { return NumTraits<Scalar>::digits10(); }
    };

    /** \internal
  * print the matrix \a _m to the output stream \a s using the output format \a fmt */
    template <typename Derived> std::ostream& print_matrix(std::ostream& s, const Derived& _m, const IOFormat& fmt)
    {
        using internal::conditional;
        using internal::is_same;

        if (_m.size() == 0)
        {
            s << fmt.matPrefix << fmt.matSuffix;
            return s;
        }

        typename Derived::Nested m = _m;
        typedef typename Derived::Scalar Scalar;
        typedef typename conditional<
            is_same<Scalar, char>::value || is_same<Scalar, unsigned char>::value || is_same<Scalar, numext::int8_t>::value ||
                is_same<Scalar, numext::uint8_t>::value,
            int,
            typename conditional<is_same<Scalar, std::complex<char>>::value || is_same<Scalar, std::complex<unsigned char>>::value ||
                                     is_same<Scalar, std::complex<numext::int8_t>>::value || is_same<Scalar, std::complex<numext::uint8_t>>::value,
                                 std::complex<int>,
                                 const Scalar&>::type>::type PrintType;

        Index width = 0;

        std::streamsize explicit_precision;
        if (fmt.precision == StreamPrecision)
        {
            explicit_precision = 0;
        }
        else if (fmt.precision == FullPrecision)
        {
            if (NumTraits<Scalar>::IsInteger)
            {
                explicit_precision = 0;
            }
            else
            {
                explicit_precision = significant_decimals_impl<Scalar>::run();
            }
        }
        else
        {
            explicit_precision = fmt.precision;
        }

        std::streamsize old_precision = 0;
        if (explicit_precision)
            old_precision = s.precision(explicit_precision);

        bool align_cols = !(fmt.flags & DontAlignCols);
        if (align_cols)
        {
            // compute the largest width
            for (Index j = 0; j < m.cols(); ++j)
                for (Index i = 0; i < m.rows(); ++i)
                {
                    std::stringstream sstr;
                    sstr.copyfmt(s);
                    sstr << static_cast<PrintType>(m.coeff(i, j));
                    width = std::max<Index>(width, Index(sstr.str().length()));
                }
        }
        std::streamsize old_width = s.width();
        char old_fill_character = s.fill();
        s << fmt.matPrefix;
        for (Index i = 0; i < m.rows(); ++i)
        {
            if (i)
                s << fmt.rowSpacer;
            s << fmt.rowPrefix;
            if (width)
            {
                s.fill(fmt.fill);
                s.width(width);
            }
            s << static_cast<PrintType>(m.coeff(i, 0));
            for (Index j = 1; j < m.cols(); ++j)
            {
                s << fmt.coeffSeparator;
                if (width)
                {
                    s.fill(fmt.fill);
                    s.width(width);
                }
                s << static_cast<PrintType>(m.coeff(i, j));
            }
            s << fmt.rowSuffix;
            if (i < m.rows() - 1)
                s << fmt.rowSeparator;
        }
        s << fmt.matSuffix;
        if (explicit_precision)
            s.precision(old_precision);
        if (width)
        {
            s.fill(old_fill_character);
            s.width(old_width);
        }
        return s;
    }

}  // end namespace internal

/** \relates DenseBase
  *
  * Outputs the matrix, to the given stream.
  *
  * If you wish to print the matrix with a format different than the default, use DenseBase::format().
  *
  * It is also possible to change the default format by defining EIGEN_DEFAULT_IO_FORMAT before including Eigen headers.
  * If not defined, this will automatically be defined to Eigen::IOFormat(), that is the Eigen::IOFormat with default parameters.
  *
  * \sa DenseBase::format()
  */
template <typename Derived> std::ostream& operator<<(std::ostream& s, const DenseBase<Derived>& m)
{
    return internal::print_matrix(s, m.eval(), EIGEN_DEFAULT_IO_FORMAT);
}

}  // end namespace Eigen

#endif  // EIGEN_IO_H
